package com.jsj.hn.servlet.gb;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.List;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/ValidateCodeServlet")
public class ValidateCodeServlet extends HttpServlet {
	
	private static final long serialVersionUID = 1L;
	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		request.setCharacterEncoding("UTF-8");
		response.setContentType("image/jpeg");
		ServletOutputStream out=response.getOutputStream();
		//创建缓冲图像
		int width=60;
		int height=20;
		BufferedImage imbuf=new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		Graphics2D g=imbuf.createGraphics();
		//设定背景色
		g.setColor(getRandColor(200, 250));
		//设定图像形状及宽高
		g.fillRect(0, 0, width, height);
		//随机产生100条干扰线，使图像中的认证码不易被其他程序检测
		Random r=new Random();
		g.setColor(getRandColor(160, 200));
		for(int i=0;i<100;i++) {
			int x=r.nextInt(width);
			int y=r.nextInt(height);
			int x1=r.nextInt(12);
			int y1=r.nextInt(12);
			g.drawLine(x, y, x+x1, y+y1);
		}
		//随机产生100条干扰点，使图像中的认证码不易被其他程序检测
		g.setColor(getRandColor(120, 240));
		for(int i=0;i<100;i++) {
			int x=r.nextInt(width);
			int y=r.nextInt(height);
			g.drawOval(x, y, 0, 0);
		}
		//随机产生0~9之间的4个数字
		g.setFont(new Font("Times New Roman",Font.PLAIN,18));
		String code="";
		for(int i=0;i<4;i++) {
			String rand=String.valueOf(r.nextInt(10));
			code+=rand;
			g.setColor(new Color(20+r.nextInt(110),20+r.nextInt(110),20+r.nextInt(110)));
			g.drawString(rand, 13*i+6, 16);
		}
		//将验证码保存到Session
		request.getSession().setAttribute("ValidateCode", code);
		//输出图像
		ImageIO.write(imbuf, "JPEG", out);
		out.close();
	}
	@Override
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		this.doGet(request, response);
		
	}
	private Color getRandColor(int fc,int bc) {
		Random random=new Random();
		if(fc>255)
			fc=255;
		if(fc<0)
			fc=0;
		if(bc>255)
			bc=255;
		if(bc<0)
			bc=0;
		int r=fc+random.nextInt(bc-fc);
		int g=fc+random.nextInt(bc-fc);
		int b=fc+random.nextInt(bc-fc);
		return new Color(r,g,b);
	}
}
